CVE-2026-56740
JLine: Unauthenticated Remote Memory Exhaustion via Unbounded Telnet NEW-ENVIRON Variables
HIGH 7.5
At a glance
- Source
- NVD
- EPSS
- EPSS 0.88 % · percentile 59 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
JLine is a Java library for handling console input. Prior to 3.30.14, 4.0.16, and 4.2.1, the JLine3 Telnet server remote-telnet module does not limit the number of environment variables a client may inject via the Telnet NEW-ENVIRON option, and TelnetIO.readNEVariables() in TelnetIO.java:1127-1180 stores each variable pair in a HashMap held by ConnectionData, allowing an unauthenticated attacker to flood unique variable pairs before the terminating IAC SE byte and exhaust JVM heap memory with an OutOfMemoryError. This issue is fixed in versions 3.30.14, 4.0.16, and 4.2.1.
Weaknesses (CWE)
- CWE-400 — Uncontrolled Resource Consumption (DoS)
References
- https://github.com/jline/jline3/security/advisories/GHSA-47qp-hqvx-6r3f
- https://github.com/jline/jline3/pull/2000
- https://github.com/jline/jline3/pull/2001
- https://github.com/jline/jline3/commit/0389f0ee6d0375901b602671ad5dafd4d1d4ee09
- https://github.com/jline/jline3/commit/4ee3a73849ffb9a85ec748e4e8cd8f6d81f84f40
- https://github.com/jline/jline3/commit/934f09e6128cee33c2b13d42b6e859c1ee2d194b
- https://github.com/jline/jline3/releases/tag/4.0.16
- https://github.com/jline/jline3/releases/tag/4.2.1
- https://github.com/jline/jline3/releases/tag/jline-3.30.14
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-47qp-hqvx-6r3f — JLine3 Telnet server: Unauthenticated Remote Memory Exhaustion via Unbounded Telnet NEW-ENVIRON Variables
European references
- ENISA EUVD · EUVD-2026-45343
- GCVE · GCVE-0-2026-56740
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:jline:jline:*:*:*:*:*:*:*:*< 3.30.14cpe:2.3:a:jline:jline:*:*:*:*:*:*:*:*≥ 4.0.0 < 4.0.16cpe:2.3:a:jline:jline:*:*:*:*:*:*:*:*≥ 4.1.0 < 4.2.1
Affected products
| Product | Versions |
|---|---|
| jline · jline3 | affected < 3.30.14 ; affected >= 4.0.0, < 4.0.16 ; affected >= 4.1.0, < 4.2.1 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |